Sensation is the process of detecting and encoding of physical energy from the environment into neural signals Perception is the process of recognizing, organizing, and interpreting sensory information Two Theories of Processing
•Bottom-up theories
• -Parts are identified, put together, and then recognition occurs
•Top-down theories
• -People actively construct perceptions using information based on expectations
Thresholds
Absolute Threshold - The minimum amount of a stimulation needed to detect a particular stimulus.
-Amount of a stimulus that a person can detect 50% of the time
Difference Threshold - The minimum amount of difference needed to detect that two stimuli are not the same.
-Weber’s Law- Difference threshold is in proportion to the stimulus. It is more difficult to recognize a small differene in larger stimuli than it is in smaller stimuli Sensory adaptation
-Occurs when sensory receptors change their sensitivity to the stimulus
-Constant stimulation leads to lower sensitivity
-The brain is constantly processing and adjusting its perception of sensory input Sensory Adaptation can lead to After Images • After Images in Light and Darkness, Color, and Motion
Signal Detection Theory
A theory that predicts how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise).
Perception is the process of recognizing, organizing, and interpreting sensory information
Two Theories of Processing
- • Bottom-up theories
- • -Parts are identified, put together, and then recognition occurs
- • Top-down theories
- • -People actively construct perceptions using information based on expectations
ThresholdsAbsolute Threshold - The minimum amount of a stimulation needed to detect a particular stimulus.
-Amount of a stimulus that a person can detect 50% of the time
Difference Threshold - The minimum amount of difference needed to detect that two stimuli are not the same.
-Weber’s Law- Difference threshold is in proportion to the stimulus. It is more difficult to recognize a small differene in larger stimuli than it is in smaller stimuli
Sensory adaptation
-Occurs when sensory receptors change their sensitivity to the stimulus
-Constant stimulation leads to lower sensitivity
-The brain is constantly processing and adjusting its perception of sensory input
Sensory Adaptation can lead to After Images
• After Images in Light and Darkness, Color, and Motion
Signal Detection Theory
A theory that predicts how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise).
Developed out of the Cold War